The present invention relates generally to automobile and cargo transport, and more particularly, to a ratcheting tie down apparatus and system.
FIG. 1 illustrates a prior art vehicle transport trailer 100. Several vehicles 105 can be transported on the trailer. Each of the vehicles typically has its own platform 110 onto which each vehicle 105 is secured.
FIG. 2 illustrates a side view of a prior art vehicle trailer tie down system 101. As previously described, each vehicle 105 is secured to its platform 110. FIG. 2 illustrates the vehicle 105 tied to its platform 110 by straps 115 arranged around each wheel 106 of the vehicle 105. The vehicle 105 is typically restrained to the platform 100, and therefore the trailer, by arranging the straps 115 to the wheels 106 of the vehicle 105 and the platform 110 or other part of the trailer. The straps 115 are placed in tension to prevent movement.
FIG. 3 illustrates a top perspective view of the prior art vehicle trailer tie down system 101 of FIG. 2. Currently, locking mechanisms 120 are implemented to keep the straps 115 from loosening due to forces acting upon the vehicle 105 (e.g. gravity, centripetal and other forces asserted on the vehicle 105 from the trailer or otherwise). There are many types of mechanisms 120 such as ratchet and clamping devices that are typically manually tightened. For example, one end of the strap 115 can be connected to a fixed hook 125 that can be fixed to multiple slots 130 on the platform 110. The strap 115 can then be routed through an intermediate hook 135 also placed in one of the multiple slots 130 on the platform 110. The strap 115 can then be connected to a shaft 140 of the mechanism 120. Current ratchet 145 and pawl 150 mechanisms are implemented to tighten the strap 115 around the shall. The overall tie down system can include a gear casting 146 with ramping surfaces 147 engaged with a pawl 150. The ramping surfaces allow gear rotation in one direction, but stop rotation in the other direction due to engagement with the pawl 150. The shaft 140 is affixed to the gear casting 146. Currently, the shaft 140 can be equipped with either a chain attachment mechanism, or a strap attachment mechanism. Integral to the gear casting 146 is a protrusion 148 with a series of cross-holes 149 that are perpendicular to the rotational axis of the gear casting 146.
In operation, a tie down bar 170 is inserted into these cross-holes and force is applied to the tie down bar 170, which creates a torque about the shaft 140. The torque is transmitted into tension in the chain or strap that is attached to the shaft 140. Typically, the tie down 170 bar can be rotated about 60 degrees at a time. If this rotation does not take up sufficient slack in the chain or strap, then the tie down bar 170 is pulled out of the current cross-hole 149, reinserted into the next convenient cross hole 149, and rotated again. This action may be repeated many times.